It is well known in the lawn sprinkler art to provide apparatus for adjusting the height of a sprinkler head relative to the surrounding ground level. For example, U.S. Pat. No. 3,084,869 to Hutty et al discloses an adjustable sprinkler in which height adjustment is accomplished by rotating an inner pipe section to permit axial adjustment thereof relative to an outer pipe section. Another patent which employs an adjustable extension for sprinkler systems in U.S. Pat. No. 1,833,040 to Rader. In this patent, rotation of an inner pipe member will raise the inner member relative to an outer pipe member to adjust the height thereof. A different type of adjustable arrangement is disclosed in U.S. Pat. No. 3,684,179 to Fischer et al. In this patent, a pin is mounted on an inner tube member, and the height to which the sprinkler head is extended may be adjusted by rotating the inner tube member and pin relative to a coil spring which vertically displaces the inner tube relative to an outer tube.
Accordingly, although the prior art discloses a number of ways for adjusting the height of a lawn sprinkler, it does not appear that the prior art discloses the concept of a replaceable sprinkler assembly in which the sprinkler assembly or parts thereof may be replaced to accommodate changes in surrounding soil or grass level, and to allow for easy maintenance of the lawn sprinkler. In addition, conventional lawn sprinklers do not appear to be constructed and arranged to receive therein sprinkler assemblies of different heights in accordance with the surrounding ground level; in contrast, conventional lawn sprinklers primarily appear to be adjustable by varying the relative position of two telescopically arranged inner and outer pipes. Therefore, the longitudinal dimension of the outer pipe places an upper limit on the longitudinal dimension of the inner pipe, which is housed or completely received within the outer pipe. Accordingly, the extent to which conventional lawn sprinklers may be adjusted is usually limited to a narrow range controlled by the dimensions of the inner and outer pipes.
Further, conventional lawn sprinklers, which are of the adjustable type, are not constructed and arranged for easy replacement of parts or for easy maintenance due to their rather complex structure. Typically, for replacement and/or maintenance purposes, the entire lawn sprinkler must be disconnected from the underground water supply system so that the lawn sprinkler may be serviced.
In view of the foregoing, present lawn sprinklers, although adjustable, have serious drawbacks with respect to their limits of adjustability to accommodate surrounding ground levels as they change, and with respect to the replacement of parts and normal maintenance.
Therefore, it is an object of the present invention to provide an improved lawn sprinkler, which is easily adjustable over a wide range and which is easy and inexpensive to maintain, as it may be quickly disassembled for replacement of the sprinkler assembly or parts thereof to accommodate changes in surrounding ground level, or to perform normal maintenance operations.